The present invention relates generally to the field of manufacturing systems, and more particularly to a stand alone unit or module used to facilitate the interface or communication between elements in a system for processing articles, such as semiconductor wafers.
Pursuant to 37 C.F.R. xc2xa71.96(c), a computer program listing appendix incorporating features of the present invention is being submitted herewith on a compact disc in compliance with 37 C.F.R. xc2xa71.52(e), and is incorporated herein by reference in its entirety. The computer program listing appendix is being submitted on a compact disc labeled xe2x80x9cCopy 1xe2x80x9d. A duplicate copy labeled xe2x80x9cCopy 2xe2x80x9d is also enclosed. The content and information contained on each disc is identical, the details of which are as follows:
Machine Format: IBM(trademark)-PC
Operating System Compatibility: MS-Window(trademark) (LOTUS WordPro(trademark))
File on CD:
Name: 09_207_957Appendix1.18.02.lwp
Size: 38.3 MB
Date: Jan. 18, 2002
The field of semiconductor wafer manufacturing has seen the development of technologies which minimize wafer contamination, thus maximizing yields, through the use of sealed pods or containers for transporting wafers to be processed from one processing tool to another and to and from storage areas. Access to the wafers within the containers is had through a standard mechanical interface (SMIF). For example, see U.S. Pat. No. 4,532,970. Fabrication systems using such pods have come to be known as SMIF fabs and the containers have come to be known as SMIF pods.
The system for processing wafers in a SMIF fab will typically include a SMIF pod for carrying the wafers, a machine or processing tool (having a processing controllerxe2x80x94referred to as the xe2x80x9chostxe2x80x9d) for processing the wafers, a robot which is connected to the machine tool for receiving the pod and for transporting the wafers from within the pod into position on the machine tool for processing, and an identification system to permit identification of a pod. The identification system will consist of an identifying tag on the pod, such as a bar code or RF transponder, and a reader. The type of reader will depend on the type of identifying tag.
In a typical existing installation the identification system would be connected to a Cell Controller which manages the process tools via a terminal server or similar hardware and then via separate connections to the robot at each tool port. In addition, the Cell Controller would be separately connected with the process tools and their associated robots.
This arrangement is complicated since there are numerous tools within a fab and for each tool and its associated robot there are various data collection points for monitoring the environment and the articles being processed. Therefore a number of different data inputs is required. Currently, a separate computer is required to coordinate the collection of these inputs. In addition, for each of the numerous tools in a fab there is the problem of determining where to locate antennae, controllers and power supplies required to effect proper communication. Positioning of the antennae and other components significantly complicates the design of any fab.
Further, the use of an additional computer to effect communication requires means of interfacing with such computer and integrating with the various tools.
It is accordingly a principal object of the present invention to overcome the foregoing difficulties and disadvantages.
It is a specific object of the invention to simplify the current connection arrangement, discussed above, by providing a single wire interface between a process tool, the identification system, and the robot of that tool to the Cell Controller. Accordingly, this invention provides a module which includes a reader for reading the identification tag, and a micro circuit to provide a connection route between the identification system and the host, and between the host and the robot.
Another object of the invention is to provide a simplified connection using lower power consumption and modular design so that it can be easily installed.
Other objects, features and advantages of the present invention will be apparent from the description hereinafter.
In a semiconductor wafer processing system, the identification system could be of the typical RF reader and transponder type, or of a bar code type, or of an IR transceiver type. The robot could be of a well know structure for receiving the pod of wafers and moving the wafers into position where the process tool will have access to the pod for treating the wafers. The host can either be integral with the tool or may consist of a computer network for providing control and instruction to each of the tools.
In operation, the RF Reader of the identification system (or in the case of a bar code the optical reader, or in case of an IR system, the IR transceiver) would be mounted on or in the robot in such a manner as to permit reading the identification tag when the pod is properly placed on a receiving port of the robot. The tag will be read upon command of the host upon receipt of a message from the robot that a pod has been placed for processing. All messages and commands from the host via the present invention are simply passed to the proper recipient without respect to the contents of the message or command. The module of this invention does not provide message processing, only message routing. Once the host has determined that the pod is in position it will then communicate through the module to the robot to instruct the robot to begin its operation on the pod allowing the process tool access to the wafers. The module does not communicate directly with the pod or robot, either through the identification system or other means, and does not require any type of data storage or processing capability on the pod to facilitate additional process requirements of the wafers contained within the pod.
The present invention thus operates as a distribution system. It is capable of recognizing the source of information and routing it to the proper recipient. For example, the signal coming from the identification system would be routed to the host. Similar signals that may come from the robot to indicate that it has received the pod would also be routed to the host, and signals directed to the robot from the host to perform certain functions would be routed through the module.
The present invention uses lower power to effect communication, is faster and less expensive than current techniques, and is a stand alone module that can be easily installed in a variety of fabs. The use of this invention does not require reconfiguration of robots or tools and it can interface with many different existing robots produced by different manufacturers.
In addition to the foregoing, the present invention can interface with guided vehicles used in a fab for transporting wafer containers.
The foregoing and other features of the present invention are more fully described with reference to the following drawings annexed hereto.